Ingredient review

Acrylates/Steareth-20 Methacrylate Crosspolymer

INCI: ACRYLATES/STEARETH-20 METHACRYLATE CROSSPOLYMER

A safe, effective thickener that gives lightweight, non-greasy textures to water-based skincare products.

beautyskincarethickener

In plain English

This is a synthetic ingredient that helps give skincare products a smooth, gel-like feel without making them sticky or heavy. It works by forming a network in water that thickens the formula and keeps other ingredients evenly mixed. You'll find it in lightweight serums, gel moisturizers, and sunscreens where a silky, non-greasy texture is desired.

Quick decision guide

Useful, but context matters

Acrylates/Steareth-20 Methacrylate Crosspolymer is generally a lower-concern ingredient when the full formula suits your skin.

Plain-English read

Treat this as a practical screening step before you compare products that contain this ingredient.

  1. Step 1Start with the score, then check the irritation and clogging risk before judging Acrylates/Steareth-20 Methacrylate Crosspolymer.
  2. Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
  3. Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.

Score terms in plain English

Irritation risk

low

Less likely to sting, burn, or bother most users, though sensitive skin can still react.

Clogging risk

low

Less likely to feel heavy or contribute to clogged pores for most skin types.

Evidence level

moderate

There is useful support, but formula details and claim strength still matter.

What it is

A synthetic polymer made from acrylic acid and a fatty alcohol derivative (steareth-20). It is a crosspolymer, meaning its molecules are linked together in a 3D network that can absorb water and swell, creating a gel.

How it works

When added to water, the polymer chains unwind and form a mesh that traps water molecules, increasing the viscosity (thickness) of the product. This also helps suspend other ingredients like oils or pigments, preventing separation. It is often used in combination with neutralizing agents (like triethanolamine) to activate its thickening power.

Pros

Lightweight texture

Provides a silky, non-sticky feel that absorbs quickly, making it ideal for serums and gel moisturizers.

Excellent stability

Helps keep water and oil phases mixed, preventing your product from separating or changing consistency over time.

Cons and cautions

Synthetic origin

Not derived from natural sources, which may be a concern if you prefer a fully natural skincare routine.

Formulation sensitivity

Its thickening ability can be affected by high salt concentrations or extreme pH levels, though this is rarely an issue in well-formulated products.

Best for

  • Anyone who prefers lightweight, gel-based skincare
  • People with oily or combination skin looking for non-greasy hydration

Use caution if

  • Those seeking 100% natural or plant-based ingredients

Usage tips

Look for this ingredient in gel-based serums and lightweight moisturizers for a refreshing feel.
It works well with water-soluble actives like hyaluronic acid and niacinamide.

Safety summary

Acrylates/Steareth-20 Methacrylate Crosspolymer is considered safe for use in cosmetics. It has a low irritation and comedogenic risk, making it suitable for most skin types, including sensitive skin.

Research notes

Safety assessments by the Cosmetic Ingredient Review (CIR) panel have concluded that this ingredient is safe in cosmetic formulations at typical use concentrations. No significant toxicity or sensitization concerns have been identified in available studies.

Common label clues

Typical concentration
0.1% to 2% of the formula
Regulatory status
Approved for use in cosmetics in the US, EU, and other major markets. The Cosmetic Ingredient Review (CIR) panel has deemed it safe as used.
Common uses
Serums, Gels, Moisturizers, Sunscreens, Makeup primers
Environmental note
As a synthetic polymer, it is not biodegradable. However, it is used in very small amounts and is not known to accumulate in the environment.

Good to know

  • This ingredient is often used in 'jelly' or 'water cream' textures that are popular in Korean skincare.
  • It is considered safe and non-irritating by major regulatory bodies.

Common questions

What is Acrylates/Steareth-20 Methacrylate Crosspolymer in beauty products?

This is a synthetic ingredient that helps give skincare products a smooth, gel-like feel without making them sticky or heavy. It works by forming a network in water that thickens the formula and keeps other ingredients evenly mixed. You'll find it in lightweight serums, gel moisturizers, and sunscreens where a silky, non-greasy texture is desired.

What does Acrylates/Steareth-20 Methacrylate Crosspolymer do in a beauty product?

When added to water, the polymer chains unwind and form a mesh that traps water molecules, increasing the viscosity (thickness) of the product. This also helps suspend other ingredients like oils or pigments, preventing separation. It is often used in combination with neutralizing agents (like triethanolamine) to activate its thickening power.

Is Acrylates/Steareth-20 Methacrylate Crosspolymer safe for most people?

Acrylates/Steareth-20 Methacrylate Crosspolymer is considered safe for use in cosmetics. It has a low irritation and comedogenic risk, making it suitable for most skin types, including sensitive skin.

Who should be careful with Acrylates/Steareth-20 Methacrylate Crosspolymer?

Those seeking 100% natural or plant-based ingredients

Research sources

Cosmetic Ingredient Review (CIR) Safety AssessmentOpenEuropean Chemicals Agency (ECHA) InformationOpenPubChem Compound SummaryOpen

Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.